Since when analog broadcast receivers had predominated, techniques for displaying plural programs on one display unit have been used. Furthermore, at the present time when digital broadcast receivers are becoming mainstream, devices capable of multi-screen display are growing popular. For example, for the digital broadcast receiver disclosed in patent document 1, patent document 1 discloses a technique for display two screens of a TV display screen and an Internet screen and also discloses a technique for smoothly switching these screens.    Patent Document 1: JP Patent Publication (Kokai) No. 2005-244716A